It is common knowledge among Wi-Fi professionals that using 20 MHz or 40 MHz channel widths when planning 5 GHz networks offers the best overall experience for enterprise networks. This is because enterprise networks can often cover large footprints and need higher density for many connected devices. Using narrower channel widths provides many more available channels for building out networks with appropriate channel reuse and allows flexibility to avoid co-channel interference from noisy neighbors.
Available 20 MHz-wide 5 GHz channels (source: PotatoFi)
Available 80 MHz-wide 5 GHz channels (source: PotatoFi)
Residential and small business Wi-Fi challenges are not so different. The average US household has 21 Wi-Fi devices1. Many homes require multiple mesh nodes or access points to cover effectively. Users in dense urban areas face many nearby access points using wide channels. Although Wi-Fi networks built by seasoned professionals typically use narrower channels, consumer Wi-Fi devices from popular manufacturers and ISPs utilize 80 MHz or wider channel widths by default. Popular routers and mesh systems from large manufacturers can even default to 40 MHz channels for 2.4 GHz networks (some not even allowing you to change to 20 MHz), utilizing two-thirds of the available spectrum!
Why? Because consumers have been conditioned to understand only raw speed as a metric of Wi-Fi quality and not more important indicators of internet experience such as responsiveness and reliability. If manufacturers shipped Wi-Fi routers and mesh systems that utilized more reasonable 40 MHz-wide 5 GHz channels out of the box, consumers would return the products when their favorite speed testing tool showed no improvement in speed over their previous system. Similarly, ISPs are reluctant to configure consumer premise equipment (CPE) to use narrower channels by default to reduce adjacent-channel and co-channel interference, as this will decrease the maximum achieved speed and hurt their standings in network performance benchmarks that emphasize raw speed over a rock solid and consistent Wi-Fi experience.
But wait. It gets worse.
Not only does consumer and telecoms marketing’s heavy focus on speed hamstring ISPs and device manufacturers when it comes to delivering excellent in-home Wi-Fi, but the very act of performing speed tests negatively impacts experience.
For example, here is a 1-minute summary of an iPhone’s responsiveness connected to a Wi-Fi 6 router connected directly to a symmetrical 1 Gbps fiber connection.
Orb 1-minute Wi-Fi Responsiveness view, idle network
Now, an important concept in Wi-Fi is that of airtime contention: basically, only a single device can “talk” at a time on a given channel2. So if one device is generating a considerable amount of unnecessary traffic, say from taking an internet speed test, substantial airtime contention occurs. Let’s connect a laptop to the same Wi-Fi router, take an internet speed test, and observe the impact on responsiveness from the same iPhone:
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